Improvement in driers for lead



A. D. ARMSTBUN G.

Drers for Lead.

Patented Dec- 23,1873

UNITED STATES PATENT CEEIcE.

ANDREW I). ARMSTRONG, OF ALLEGHENY CITY, ASSIGNOR TO ARMSTRONG, FAWCETT85 MCKELVY, OF PITTSBURG, PENNSYLVANIA.

IMPROVEMENT IN DRIERS FOR LEAD.

Specification forming part of Letters Patent No. 145,713, dated December23, 1873; application led July 11, 1873.

To all whom Muay concern:

Be itknown that I, ANDREWD. ARMSTRONG, of Allegheny City, in the countyof Allegheny and State of Pennsylvania, have invented a new and usefulImprovement in Apparatus for Drying Lead; and I do hereby declare thefollowing to be a full, clear, and eXact description thereof, referencebeing had to the accompanying drawing forming a part of thisspeciiication, in which- Figure l is a perspective view of my improveddrying apparatus. the cover of the same being opened; and Fig. 2 is alongitudinal section of the same.

Like letters of reference indicate like parts in each.

My invention consists in the construction of an improved drying-kiln,for the purpose of drying White lead, in which heat is applied to thelower side by means of a jet of steam, and

which heat has been applied. This method requires several days for itscompletion.

To enable others skilled in the art to make and use my invention, I willdescribe its construction and mode of operation.

The carbonate of lead, or, as it is usually called, white lead,77 havingbeen previously prepared in the usual way, is in the form of a coarsemortar, and while in this condition is ground very fine by means of aburr, in the usual way. In the operation of grinding', water issupplied. After being ground the lead is run into a vat, in which it isallowed to stand until the lead is precipitated to the botltom, and thenthe water is drawn oit' by means ing the upper compartment, a2. Thesteam escapes from the compartment al through the pipe d. The uppercompartment, c2, is provided with a cover, e, which iits down over thesteam-pipe d, and which has an opening, f, at one end. Opening into theopposite end of the compartment a2 is a hot-air pipe, g, the mouth g ofwhich extends across the entire end of the compartment a2. The lead isplaced in the compartment a2, and the lid e shut down and secured; thena jet of steam is injected into the compartment al through the pipe c,

j' at the opposite end of the kiln. The steam and air are supplied untilthe operation of drying is complete.

By means of this apparatus applying the heat not only to the under sideof the leadchamber a2, but also directly to the surface of the lead, theoperation of dryingl lead requires about lifteeu hours, while the oldmethod occupied at least three days, and frequently more.

In order to economize fuel, I so arrange the steam-pipe inside of asuitable box that it shall heat the air, which is supplied by means ofthe blast for drying the lead in the compartment a2. The manner in whichthis can be done is familiar to the skilled mechanic. Y

What I claim as my invention and desire to secure by Letters Patent, is-

A stationary drying -tank, a, divided hori- Zontally into two chambers,al and a2, the iirst being iitted with steam supply and discharge pipesc and d, and the latter with a broadmouthed blast-pipe, g, an exit, f,and a lid, c, substantially as described.

In testimony whereof I, the said ANDREV'T D. ARMSTRONG, have hereuntoset my hand.

ANDREWT D.'ARMSTRONG.

Vitnesses v T. B. KEER, JAMES I. KAY.

